If you have to write a check with a lot of zeroes in it, you might have to make out 2 checks.

If you have to write a check with a lot of zeros in it, you might have to make out 2 checks to the U.S. Treasury instead.

What’s the largest tax payment check you’ve ever written?

If you find you need to send the U.S. Treasury $100 million or more, beginning next year you’ll have to split that amount into 2 checks.

No kidding. A handful of taxpayers have sent the IRS such huge payments. This latest tax season, 14 such checks were received, according to a memo from the agency’s Wage and Investment Division.

While the IRS is happy to get the money, it does pose problems when it comes in such large chunks. Really big checks have to be processed manually.

So the IRS will stop accepting checks of more than $99,999,999 effective Jan. 1, 2016. After that date, you’ll have to send in at least 2 checks to cover your big tax bill.

Or, says the IRS, you can still send 1 large payment if you electronically wire it to the appropriate Federal Reserve bank.

Manual processing problems

In announcing the upcoming limit on big checks in the Sept. 7 Internal Revenue Bulletin, the IRS cited an earlier memo from the Treasury’s Bureau of the Fiscal Service that noted the risks of manually processing checks of $100 million or more.

“Fraudulent activity, processing errors and uncollectible funds are more likely when checks over these amounts are accepted by TGA (Treasury General Account) depositaries,” wrote David M. Metler, director, over-the-counter division of the Treasury Bureau of the Fiscal Service. “No check processing equipment can handle amounts over a million dollars.”

Although the manual processing kicks in at $1 million, the IRS still will take checks up to $99,999,999 million, for now.

Estimated tax issues

OK, most of us won’t ever have to worry about dashing off such a ginormous check to Uncle Sam to cover our taxes. But sometimes we do end up paying more than we expected.

That’s often the case when you should be making estimated tax payments but don’t. Or you vastly underestimate how much you should be paying each quarter.

If you are paying estimated taxes, don’t forget that the 3rd payment for the 2015 tax year is due in a week, on Tuesday, Sept. 15. You might want to double-check that you’re sending in the appropriate amount on that day.

If you’re off, you’ll end up having to come up with a large lump-sum payment when you file your 2015 return. You’ll also end up facing underpayment penalties and interest.

Pay quarterly, or pay more April 15

Trust me. You want to get your 1040ES payment right. I didn’t one year and had to send a 5-figure tax check to Uncle Sam.

It was more than 2 decades ago, when the hubby was in a job transition and spent about a year making good money as an independent contractor. I forgot about calculating his self-employment taxes as part of the total estimated tax payment amount.

That April 15 still stands as the worst Tax Day ever.

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